FESTO Pneumatics & All Fluid Accessories Knuckle joint 611138 - FESTO 3110, The FESTO Knuckle Joint 3110 SG-M6 is a versatile mechanical linkage component featuring high durability and precision engineering. Manufactured by FESTO, it is designed for flexible joint connections, typically used in pneumatic and automation systems. Its robust construction ensures reliable performance in industrial machinery applications. FESTO 3110 Knuckle joint durable M6 attachment 1pc